Method of manufacturing rotor for dynamoelectric machine

a technology of dynamoelectric machines and rotors, which is applied in the direction of manufacturing stators/rotors, manufacturing tools, and manufacturing tools, etc., can solve the problems of permanent magnets being undetected magnets and permanent magnets becoming incapable of performing the function

Active Publication Date: 2013-04-30
DENSO CORP
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  • Summary
  • Abstract
  • Description
  • Claims
  • Application Information

AI Technical Summary

Benefits of technology

This approach reduces the necessary weld current, allows for the use of a smaller power source, and minimizes the risk of magnetizing permanent magnets, resulting in more reliable and high-quality welds between the cooling fan and rotor core.

Problems solved by technology

However, when a large amount of the weld current flows through the pole core 100 which is to be joined to the cooling fan 120, the permanent magnets may be undesirably magnetized by a magnetic field created by the weld current.
As a result, the permanent magnets may become unable to accomplish the function of reducing the leakage magnetic flux.

Method used

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  • Method of manufacturing rotor for dynamoelectric machine
  • Method of manufacturing rotor for dynamoelectric machine
  • Method of manufacturing rotor for dynamoelectric machine

Examples

Experimental program
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Effect test

first embodiment

[0035]FIG. 1 shows the overall configuration of an automotive alternator 1 which includes a rotor 3 manufactured by a method according to the first embodiment of the invention. The alternator 1 is designed to be used in a motor vehicle, such as a passenger car or a truck.

[0036]As shown in FIG. 1, the alternator 1 includes a stator 2, the rotor 3, a pair of housings 4 and 5, a brush assembly 6, and a rectifier 7.

[0037]The stator 2 includes a hollow cylindrical stator core 2a and a three-phase stator coil 2b wound around the stator core 2a. The stator 2 generates three-phase AC power in a rotating magnetic field created by the rotor 3.

[0038]The rotor 3 includes a rotating shaft 9, a rotor core made up of a pair of Lundell-type pole cores 10 fixed on the rotating shaft 9, a field coil 11 wound around the pole cores 10, a pair of cooling fans 12 respectively fixed to axial end faces of the pole cores 10, and a plurality of permanent magnets 13 interposed between the pole cores 10. In ad...

second embodiment

[0064]FIG. 5 shows a cooling fan 12 according to the second embodiment of the invention.

[0065]As shown in FIG. 5, in the present embodiment, the cooling fan 12 is composed of a pair of cooling fan pieces 12A and 12B which are disposed on the same plane perpendicular to the axial direction of the rotating shaft 9 and each occupy one half of the entire angular range (i.e., 360°) of the cooling fan 12. Further, the cooling fan pieces 12A and 12B are separated from each other by an air gap 12C that extends in the radial direction of the rotating shaft 9.

[0066]In welding the cooling fan 12 to the corresponding pole core 10, for each electrode pair consisting of one of the positive electrodes 19 and one of the negative electrodes 20, the positive electrode 19 and the negative electrode 20 are respectively brought into contact with the cooling fan pieces 12A and 12C from the opposite side to the pole core 10; then, the weld current is supplied to flow from the positive electrode 19 to the ...

third embodiment

[0069]FIG. 6 shows a cooling fan 12 according to the third embodiment of the invention.

[0070]As shown in FIG. 6, in the present embodiment, the cooling fan 12 has a plurality of cuts (or slits) 21 each of which is formed between a circumferentially-adjacent pair of the blade portions 12a of the cooling fan 12. Further, each of the cuts 21 is so deeply formed in the radial direction of the rotating shaft 9 as to reach the annular connecting portion 12b. As a result, the blade portions 12a of the cooling fan 12 are connected to each other only by the annular connecting portion 12b.

[0071]In comparison, in the case of the cooling fan 12 according to the first embodiment (shown in FIG. 2A), the blade portions 12a are connected to each other not only by the annular connecting portion 12b but also by root parts of the blade portions 12a which are integrally formed without cuts 21 formed therebetween.

[0072]In the present embodiment, in welding the cooling fan 12 to the corresponding pole c...

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Abstract

There is disclosed a method of manufacturing a rotor for a dynamoelectric machine. The rotor includes a rotating shaft, a rotor core fixed on the rotating shaft, and a cooling fan fixed to an axial end face of the rotor core. The method includes the step of fixing the cooling fan to the axial end face of the rotor core by resistance welding. The method is characterized in that in the resistance welding, both a positive electrode and a negative electrode are first brought into contact with the cooling fan to have the cooling fan held between the axial end face of the rotor core and both the positive and negative electrodes, and then weld current is supplied to flow from the positive electrode to the negative electrode.

Description

CROSS-REFERENCE TO RELATED APPLICATION[0001]This application is based on and claims priority from Japanese Patent Application No. 2008-241048, filed on Sep. 19, 2008, the content of which is hereby incorporated by reference in its entirety into this application.BACKGROUND OF THE INVENTION[0002]1. Technical Field of the Invention[0003]The present invention relates generally to methods of manufacturing rotors for dynamoelectric machines, such as electric motors and electric generators. More particularly, the invention relates to an improved method of fixing a cooling fan to an axial end face of a rotor core by resistance welding.[0004]2. Description of the Related Art[0005]International Publication No. WO 2005 / 072902, an English equivalent of which is U.S. Patent Application Publication No. 2007 / 0040458, discloses a method of fixing a cooling fan to an axial end face of a rotor core by resistance welding. Both the cooling fan and the rotor core are included in, for example, a rotor of...

Claims

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Application Information

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Patent Type & AuthorityPatents(United States)
IPC IPC(8): H02K15/02H02K15/10
CPCB23K11/002B23K11/11H02K9/06H02K15/022B23K2201/36Y10T29/49336Y10T29/49009Y10T29/49012Y10T29/49075B23K2101/36
InventorKOJIMA, RYOTAROSUGIYAMA, YUJIMORIGUCHI, KEIGOKONDO, KOJI
OwnerDENSO CORP